水分胁迫下不同抗旱类型胡麻苗期生理生化指标变化

摘要

采用盆栽人工控水方法，研究了不同水分处理对苗期胡麻叶片相对含水量（RWC ）、过氧化氢酶（CAT ）活性、过氧化物酶（POD ）活性以及过氧化产物丙二醛（MDA ）含量和游离脯氨酸（Pro ）含量的影响。结果表明：在干旱胁迫下，不同抗旱类型的胡麻品种RWC均有不同程度的降低，在中度和重度胁迫下，RWC平均比CK降低4．36％和13．74％，即随胁迫强度的增加RWC下降幅度变大，强、弱抗旱性品种平均比CK降低7．67％和10．42％，即抗旱性强的品种RWC下降幅度相对较小；抗旱性强的品种其CAT和POD活性在中度和重度胁迫下平均比CK升高12．46％、15．14％和 65．01％、156．01％，均随胁迫的增强而增加，但抗旱性弱的品种却为46．84％、29．85％和58．73％、38．20％，呈现先增后减的趋势；MDA含量均随胁迫加剧呈上升趋势，但抗旱性强的品种MDA含量随胁迫的增强增幅较小，为2．99％；Pro含量随水分胁迫程度的加剧不断增加，且抗旱性强的品种体内游离脯氨酸积累量较高，平均升高108．64％。RWC和Pro可作为胡麻苗期抗旱性鉴定的生理指标。%This article reports the influence of water on oil flax leaf relative water content (RWC ) ,activity of cata-lase (CAT ) and peroxidase (POD ) , content of lipid peroxidation products malondialdehyde (MDA ) and free proline (Pro ) at the seedling stage ,using pot experiments with three water treatments .The results showed that the RWC of dif-ferent drought resistance varieties have different degrees of reduction .Under the moderate and severe water stress ,the average RWC decreased by 4 .36% and 13 .74% compared with CK ,the average RWC of drought-resistant and drought-sensitive varieties respectively decreased by 7 .67% and 10 .42% compared with CK ,the deought-resistant varieties de-creased less;and the average CAT and POD activity of drought-resistant varieties increased by 12 .46% ,15 .14% and 65 .01% , 156 .01% , respectively . The CAT and POD activity enhanced with the increasing of the stress , but the drought-sensitive varieties increased by 46 .84% ,29 .85% and 58 .73% ,38 .20% compared with CK ;it appears in-creasing at first and then decreasing .The content of MDA increased with the increasing of the stress ,while that of drought-resistant had a smaller increase (2 .99% ) than that of drought-sensitive .The content of Pro increased with the increasing of the water stress ,and the drought-resistant varieties had a higher accumulation of the proline ;average in-crease 108 .64% compared with CK .Overall ,RWC and Pro content can be regarded as physiological and biochemical indexes of drought resistance for oil flax at seedling stage .